Canterbury Street slip

Images, eqnz.chch.2010

Photos taken in Lyttelton following the February 22 earthquake. File ref: CCL-2011-03-05-After-The-Earthquake-P1110456 From the collection of Christchurch City Libraries

BeckerFraserPhotos February 2012 photograph 0460

Images, UC QuakeStudies

A photograph showing ragged tarpaulins that have partly slipped off the building they were intended to protect.

BeckerFraserPhotos September 2010 photograph 130

Images, UC QuakeStudies

A crack between the river bank and the footpath near the Williams Street Bridge in Kaiapoi. This crack has now largely been filled in. The visible gap shows how much the land slipped towards the river during the earthquake.

BeckerFraserPhotos March 2011 photograph 006

Images, UC QuakeStudies

A retaining wall on Sumner Road in Lyttelton that is made from local volcanic stone. A section of the wall has collapsed during the 22 February 2011 earthquake, and the bricks cleared away since. A road cone has been placed by the slip to warn drivers.

Hybrid Broadband Ground Motion Simulations of Porters Pass Earthquakes

Research papers, University of Canterbury Library

We present ground motion simulations of the Porters Pass (PP) fault in the Canterbury region of New Zealand; a major active source near Christchurch city. The active segment of the PP fault has an inferred length of 82 km and a mostly strike-slip sense of movement. The PP fault slip makes up approximately 10% of the total 37 mm/yr margin-parallel plate motion and also comprises a significant proportion of the total strain budget in regional tectonics. Given that the closest segment of the fault is less than 45 km from Christchurch city, the PP fault is crucial for accurate earthquake hazard assessment for this major population centre. We have employed the hybrid simulation methodology of Graves and Pitarka (2010, 2015), which combines low (f<1 Hz) and high (f>1 Hz) frequencies into a broadband spectrum. We have used validations from three moderate magnitude events (𝑀𝑤4.6 Sept 04, 2010; 𝑀𝑤4.6 Nov 06, 2010; 𝑀𝑤4.9 Apr 29, 2011) to build confidence for the 𝑀𝑤 > 7 PP simulations. Thus far, our simulations include multiple rupture scenarios which test the impacts of hypocentre location and the finite-fault stochastic rupture representation of the source itself. In particular, we have identified the need to use location-specific 1D 𝑉𝑠/𝑉𝑝 models for the high frequency part of the simulations to better match observations.